Method and apparatus for on-press color measurement
AssigneeGraphics Microsystems, Inc.
InventorsSteven Runyan, James R. Cox, Mark R. Blais, Donald A. Longerbeam
Life of this patent
Estimating the term…
Abstract
A color measurement system includes a measurement patch utilizable on a continuous sample of color printed matter. The patch has a first predefined shape with a color reference area centrally located on the patch and a high contrast feature located proximate to an edge of the patch. A camera scans the sample and generates a location signal upon detection of the high contrast feature which permits accurate positioning of a measurement sensor.
Claims12
In a color measurement system wherein a printed substrate is driven past a measurement head, the printed substrate including a color bar having a plurality of color measurement patches arranged across the printed substrate, each of the color measurement patches having a color reference area centrally located thereon, the improvement comprising, each color measurement patch including a first predefined shape having the color reference area therein and a high contrast feature located proximate to an edge of the first shape.
A system for measuring color on a moving sample of printed matter, said sample moving through the system in a sample-movement direction and having a cross-sample dimension which is perpendicular to the sample-movement direction, comprising:
- a plurality of measurement patches arranged to form a color bar in the cross-sample direction on the sample, each of said patches having a first predefined shape with a color reference area located thereon and a high contrast feature located proximate to an edge of the first shape;
- positioning means adjacent to the sample for traversing the sample in the cross-sample direction;
- camera means coupled to the positioning means for scanning the sample at a location determined by the positioning means and for generating location information regarding each patch and its high contrast feature;
- and
- measurement means coupled to the positioning means for illuminating and scanning the sample at a location determined by the positioning means.
A method for measuring colors on a moving sample of color printed matter, comprising:
- providing a plurality of color measurement patches in a known arrangement on the sample, each of said patches having a first predefined shape with a color reference area located thereon and a high contrast feature located proximate to an edge of the first shape;
- positioning a camera and a measurement head adjacent to the sample in an expected location for a selected patch;
- capturing an image of the selected patch with the camera and generating actual location information therefrom;
- measuring color at a measurement target position on the color reference area of the selected patch with the measurement head;
- and
- repositioning the camera and measurement head in response to the actual information generated.
A system for measuring color on a printed substrate, comprising:
- a plurality of measurement patches arranged across the substrate, each of said patches having a first predefined shape having a color reference area located thereon and a high contrast feature located proximate to an edge of the first shape;
- means for illuminating the substrate at a selected location;
- means for capturing an image of the illuminated substrate;
- and
- means for generating location information from the captured image of the illuminated substrate.
Dependencies are inferred from the claim text.